The Honda ER4 is a 1,590 cc, inline‑four naturally aspirated petrol engine produced between 1988 and 1991. It features a dual overhead camshaft (DOHC) valvetrain and Honda's PGM-FI fuel injection system, engineered for responsive performance in compact applications. Peak output is 130 PS (96 kW) at 6,800 rpm and 140 Nm of torque at 5,300 rpm, delivering a high-revving character ideal for spirited driving.
Fitted primarily to the European-market Honda Civic Si (EF8, EF9 chassis) and CR-X (EF8), the ER4 was designed for drivers seeking sporty handling and engine responsiveness. Emissions compliance for its production period was met through precise electronic fuel injection and catalytic conversion, aligning with Euro 1 standards.
One documented concern is premature wear of the camshaft lobes, which can lead to reduced valve lift and power loss. This issue, referenced in Honda Service Bulletin 89-033, is often linked to insufficient oil changes or use of incorrect viscosity. Honda later revised camshaft material specifications to improve durability.
Production years 1988–1991 meet Euro 1 standards (VCA UK Type Approval #VCA/EMS/HONDA-ER).
The Honda ER4 is a 1,590 cc inline‑four naturally aspirated petrol engine engineered for sport compact hatchbacks and coupes (1988-1991). It combines DOHC architecture with Honda's PGM-FI system to deliver a high-revving, responsive driving experience. Designed to meet Euro 1 standards, it prioritizes performance while maintaining emissions compliance for its era.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,590 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally Aspirated | |
| Bore × stroke | 75.0 mm × 90.0 mm | |
| Power output | 96 kW (130 PS) @ 6,800 rpm | |
| Torque | 140 Nm @ 5,300 rpm | |
| Fuel system | PGM-FI (Programmed Fuel Injection) | |
| Emissions standard | Euro 1 | |
| Compression ratio | 10.2:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Belt-driven | |
| Oil type | Honda 5W-30 or 10W-40 | |
| Dry weight | 127 kg |
The DOHC valvetrain provides a high-revving, responsive character ideal for spirited driving but requires precise oil pressure and quality to prevent camshaft lobe wear. Adherence to 10,000 km or 6-month oil change intervals is critical. Use of high-quality 5W-30 or 10W-40 oil meeting Honda specifications ensures optimal lubrication for the valvetrain. The timing belt must be replaced every 80,000–90,000 km to prevent catastrophic engine failure, as this is an interference engine. Camshaft wear issues are often traced to oil quality, with revised camshaft materials detailed in Honda SIB 89-033.
Oil Specs: Requires Honda 5W-30 or 10W-40 specification (Honda Service Manual 88-91 Civic).
Emissions: Euro 1 certification applies to all 1988–1991 models (VCA Type Approval #VCA/EMS/HONDA-ER).
Power Ratings: Measured under SAE J1349 standards (Honda Group PT‑1989).
Honda Technical Service Bulletin 89-033
Honda Service Manual (Civic 1988-1991)
VCA Type Approval Database (VCA/EMS/HONDA-ER)
The Honda ER4 was used across Honda's EF platforms with transverse mounting. This engine received platform-specific adaptations-reinforced engine mounts in the CR-X-and featured a unique intake manifold for the Civic Si trim. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front of the engine block, just below the exhaust manifold (Honda Service Manual 88-91 Civic). The 8th VIN digit for ER4-equipped vehicles is typically 'R'. Visually, the engine features a red "DOHC" logo on the valve cover. Critical differentiation from the SOHC EW/D series: The ER4 has two camshafts and a distributor mounted at the rear of the cylinder head. Service parts, particularly for the valvetrain, are specific to the ER4 and not interchangeable with other variants.
The ER4's primary reliability risk is camshaft lobe wear, with elevated incidence in vehicles with neglected oil changes. Honda SIB 89-033 identifies camshaft material as a contributing factor, while timing belt neglect remains a critical risk for all interference engines. Extended oil intervals and use of incorrect viscosity make valvetrain longevity and timing belt integrity critical.
Analysis derived from Honda technical bulletins (1988-1991) and UK DVSA failure statistics (2015-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about HONDA ER4.
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Regulation (EC) No 715/2007
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